What kind of flooring should I use in my Basement of Doom?

December 31, 2008 1:13 PM

Are there any flooring options for a concrete basement floor that occasionally gets moist from groundwater/high water table? If so, do I need to remove the paint on the floor first?

Here's the full story:

-Basement was once carpeted (by previous owners). Sewer backed up so we pulled up the carpet.
-We painted the cement floor (Sherwin-Williams concrete stain... lovely shade of blue).
-We hate the painted cement floor and want something else.
-The basement is mostly dry (no water gets in from storms, we use a humidifier, and don't have a sump pump). However, when objects (like large plastic storage totes) are on the floor, some moisture builds and mold forms. Gross.

We've been told several things so far, none of which we're totally sure about:
-We should NOT seal the concrete b/c hydrostatic pressure will cause the concrete to crack or shift over time.
-We should remove the paint b/c that seals the concrete, causing above problem.
-Carpet is fine and no vapor barrier is needed.
-Carpet is fine if a vapor barrier is used.
-Carpet is not fine at all.
(and so on with every type of flooring)

Does anyone have a similar experience and advice on flooring that will work without turning the basement into a nasty mold pit? And is the paint we used really sealing the concrete and potentially causing this mold issue and/or a later hydrostatic pressure issue?

posted by dayintoday to home & garden (10 answers total)

Well, any basement flooring advice will always begin with instructions to try to solve any moisture problems first. It doesn't sound like you have too much to worry about, but you should consider any basement flooring solution to be relatively temporary or disposable.

That said, in my basement I used a product called Delta FL. This is a dimpled plastic membrane that floats on top of the concrete (it is not attached in any way). We installed laminate flooring directly over top of the Delta FL. It's been about three years and I haven't had any problems at all. It added about $1 per square foot to the overall cost of the job.

The concept behind the Delta-FL system is that it creates a "moist" area directly above the concrete, thus equalizing the moisture level between the concrete and the air above it and preventing the continual transfer of moisture from the cement floor to the dryer household air.

If you want to install carpet over the Delta-FL, you can do so - you just need to install a plywood subfloor which you will screw to the cement floor through the Delta-FL.

Platon is another brand for this system if Delta-FL is not available. Delta-MS is a foundation cover that is functionally identical to Delta-MS, and it may be cheaper to boot.

Dri-core is a similar product that also provides an insulation layer - these are 2x2 panels with a styrofoam layer laminated to a OSB layer. This product allows you to lay carpet directly over top of it.

I wouldn't worry about the paint - if moisture wants to get through, it will bubble the paint up pretty easily.

Budget solution: go with a Delta-FL product and some sort of Laminate flooring. This is a relatively easy DIY project if you're the handyperson type.

Higher end: Dricore with carpet - the Dricore is DIYable as well, carpet is probably a pro job.
posted by davey_darling at 1:38 PM on December 31, 2008 [3 favorites]

This is incredibly helpful, thank you! I started reading about Delta-FL on your suggestion and it sounds like it was invented for exactly the problem we have. (I wish all the various flooring "experts" we talked to knew about it!) We're not a terribly handy couple, but it sounds like at least the Delta-FL part would be simple to do, and then we can either attempt laminate ourselves or get some help there.
posted by dayintoday at 2:50 PM on December 31, 2008

If you don't care about it looking super fancy, you could try large (~2 ft sq) interlocking foam flooring. I got mine at home depot, and also found it online. It's light, doesn't seem to hold water, and comes in different colors. They look a bit like large puzzle pieces.
posted by MsElaineous at 4:07 PM on December 31, 2008

davey -- do you think that Delta-FL would work on a rougher concrete floor which is dry, but dimpled/slightly pebbly and slightly chalky? (basically unfinished concrete I guess)
posted by Rumple at 4:28 PM on December 31, 2008

Rumple - It depends on how rough rough is, I suppose - is it rougher than the average sidewalk? If you showed me a pic I could give you a more educated guess. I'd be surprised to find a concrete floor in a residence that was too rough to use this product on.

I had an area of one room that was very powdery - if you swept the floor, you were literally sweeping the floor away. I laid the product over that area with no ill effect.

If there are larger indentations it is suggested that the floor be leveled (you can also layer the product to build up low areas). I didn't bother in some spots and there is a bit of a light "clack" sound when you step in that area (from the Delta-FL coming in contact with the cement floor)
posted by davey_darling at 5:17 PM on December 31, 2008

thanks davey --- I'll post a pic tomorrow or as soon as I can. I've been avoiding using a levelling compound, yet they ceiling height in my basement is only 6'4" and I really don't want to lay in a subfloor if I can help it. I'd love to be able to lay laminate over a simple product like this.
posted by Rumple at 7:13 PM on December 31, 2008

I'll check back on the thread - low headroom was exactly the reason I sought out this product as well.
posted by davey_darling at 11:09 PM on December 31, 2008

Here is a closeup of the degree of pebbling..... overall the level of the floor is not bad, it's the meso-pebbling effect....
posted by Rumple at 1:17 PM on January 3, 2009

Looking at the picture, I'd say that you're ok to use the product - you may notice a bit more noise coming from the floor when you walk over that area since it is not in complete contact with the floor at all points.

The ultimate solution for this situation would be some thinset mortar troweled on smoothly.

If it were my floor though, I'd go ahead and lay the product directly overtop.
posted by davey_darling at 12:51 PM on January 4, 2009

Here's a great Floating Ceramic Tile Flooring that you could use.
posted by dougiefresh1969 at 10:26 PM on February 6, 2009